#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2018-2019 Florent Kermarrec <florent@enjoy-digital.fr>
# Copyright (c) 2018-2019 David Shah <dave@ds0.me>
# SPDX-License-Identifier: BSD-2-Clause

import os
import argparse

from migen import *
from migen.genlib.resetsync import AsyncResetSynchronizer

from litex_boards.platforms import versa_ecp5

from litex.build.lattice.trellis import trellis_args, trellis_argdict

from litex.soc.cores.clock import *
from litex.soc.integration.soc_core import *
from litex.soc.integration.soc_sdram import *
from litex.soc.integration.builder import *
from litex.soc.cores.led import LedChaser

from litedram.modules import MT41K64M16
from litedram.phy import ECP5DDRPHY

from liteeth.phy.ecp5rgmii import LiteEthPHYRGMII

# CRG ----------------------------------------------------------------------------------------------

class _CRG(Module):
    def __init__(self, platform, sys_clk_freq):
        self.rst = Signal()
        self.clock_domains.cd_init    = ClockDomain()
        self.clock_domains.cd_por     = ClockDomain(reset_less=True)
        self.clock_domains.cd_sys     = ClockDomain()
        self.clock_domains.cd_sys2x   = ClockDomain()
        self.clock_domains.cd_sys2x_i = ClockDomain(reset_less=True)

        # # #

        self.stop  = Signal()
        self.reset = Signal()

        # Clk / Rst
        clk100 = platform.request("clk100")
        rst_n  = platform.request("rst_n")

        # Power on reset
        por_count = Signal(16, reset=2**16-1)
        por_done  = Signal()
        self.comb += self.cd_por.clk.eq(clk100)
        self.comb += por_done.eq(por_count == 0)
        self.sync.por += If(~por_done, por_count.eq(por_count - 1))

        # PLL
        self.submodules.pll = pll = ECP5PLL()
        self.comb += pll.reset.eq(~por_done | ~rst_n | self.rst)
        pll.register_clkin(clk100, 100e6)
        pll.create_clkout(self.cd_sys2x_i, 2*sys_clk_freq)
        pll.create_clkout(self.cd_init, 25e6)
        self.specials += [
            Instance("ECLKSYNCB",
                i_ECLKI = self.cd_sys2x_i.clk,
                i_STOP  = self.stop,
                o_ECLKO = self.cd_sys2x.clk),
            Instance("CLKDIVF",
                p_DIV     = "2.0",
                i_ALIGNWD = 0,
                i_CLKI    = self.cd_sys2x.clk,
                i_RST     = self.reset,
                o_CDIVX   = self.cd_sys.clk),
            AsyncResetSynchronizer(self.cd_sys,   ~pll.locked | self.reset),
            AsyncResetSynchronizer(self.cd_sys2x, ~pll.locked | self.reset),
        ]

# BaseSoC ------------------------------------------------------------------------------------------

class BaseSoC(SoCCore):
    def __init__(self, sys_clk_freq=int(75e6), device="LFE5UM5G", with_ethernet=False, with_etherbone=False, eth_phy=0, toolchain="trellis", **kwargs):
        platform = versa_ecp5.Platform(toolchain=toolchain, device=device)

        # FIXME: adapt integrated rom size for Microwatt
        if kwargs.get("cpu_type", None) == "microwatt":
            kwargs["integrated_rom_size"] = 0xb000 if with_ethernet else 0x9000

        # SoCCore -----------------------------------------_----------------------------------------
        SoCCore.__init__(self, platform, sys_clk_freq,
            ident          = "LiteX SoC on Versa ECP5",
            ident_version  = True,
            **kwargs)

        # CRG --------------------------------------------------------------------------------------
        self.submodules.crg = _CRG(platform, sys_clk_freq)

        # DDR3 SDRAM -------------------------------------------------------------------------------
        if not self.integrated_main_ram_size:
            self.submodules.ddrphy = ECP5DDRPHY(
                platform.request("ddram"),
                sys_clk_freq=sys_clk_freq)
            self.add_csr("ddrphy")
            self.comb += self.crg.stop.eq(self.ddrphy.init.stop)
            self.comb += self.crg.reset.eq(self.ddrphy.init.reset)
            self.add_sdram("sdram",
                phy                     = self.ddrphy,
                module                  = MT41K64M16(sys_clk_freq, "1:2"),
                origin                  = self.mem_map["main_ram"],
                size                    = kwargs.get("max_sdram_size", 0x40000000),
                l2_cache_size           = kwargs.get("l2_size", 8192),
                l2_cache_min_data_width = kwargs.get("min_l2_data_width", 128),
                l2_cache_reverse        = True
            )

        # Ethernet / Etherbone ---------------------------------------------------------------------
        if with_ethernet or with_etherbone:
            self.submodules.ethphy = LiteEthPHYRGMII(
                clock_pads = self.platform.request("eth_clocks", eth_phy),
                pads       = self.platform.request("eth", eth_phy))
            self.add_csr("ethphy")
            if with_ethernet:
                self.add_ethernet(phy=self.ethphy)
            if with_etherbone:
                self.add_etherbone(phy=self.ethphy)

        # Leds -------------------------------------------------------------------------------------
        self.submodules.leds = LedChaser(
            pads         = platform.request_all("user_led"),
            sys_clk_freq = sys_clk_freq)
        self.add_csr("leds")

# Build --------------------------------------------------------------------------------------------

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on Versa ECP5")
    parser.add_argument("--build",          action="store_true", help="Build bitstream")
    parser.add_argument("--load",           action="store_true", help="Load bitstream")
    parser.add_argument("--toolchain",      default="trellis",   help="FPGA toolchain: trellis (default) or diamond")
    parser.add_argument("--sys-clk-freq",   default=75e6,        help="System clock frequency (default: 75MHz)")
    parser.add_argument("--device",         default="LFE5UM5G",  help="FPGA device (LFE5UM5G (default) or LFE5UM)")
    parser.add_argument("--with-ethernet",  action="store_true", help="Enable Ethernet support")
    parser.add_argument("--with-etherbone", action="store_true", help="Enable Etherbone support")
    parser.add_argument("--eth-phy",        default=0, type=int, help="Ethernet PHY: 0 (default) or 1")
    builder_args(parser)
    soc_sdram_args(parser)
    trellis_args(parser)
    args = parser.parse_args()

    assert not (args.with_ethernet and args.with_etherbone)
    soc = BaseSoC(
        sys_clk_freq   = int(float(args.sys_clk_freq)),
        device         = args.device,
        with_ethernet  = args.with_ethernet,
        with_etherbone = args.with_etherbone,
        eth_phy        = args.eth_phy,
        toolchain      = args.toolchain,
        **soc_sdram_argdict(args)
    )
    builder = Builder(soc, **builder_argdict(args))
    builder_kargs = trellis_argdict(args) if args.toolchain == "trellis" else {}
    builder.build(**builder_kargs, run=args.build)

    if args.load:
        prog = soc.platform.create_programmer()
        prog.load_bitstream(os.path.join(builder.gateware_dir, soc.build_name + ".svf"))

if __name__ == "__main__":
    main()
